LeetCode有效的井字游戏python

https://leetcode-cn.com/problems/valid-tic-tac-toe-state/

有效的井字游戏

class Solution(object):
    def validTicTacToe(self, board):
        """
        :type board: List[str]
        :rtype: bool
        """
        FIRST,SECOND='XO'
        xnum=sum(row.count(FIRST) for row in board)
        onum=sum(row.count(SECOND) for row in board)
        
        # 检查在棋盘的 3 行，3 列和 2 条对角线上是否有该玩家的连续 3 枚棋子。
        def win(board,player):
            for i in xrange(3):
                if all(board[i][j]==player for j in xrange(3)):
                    return True
                if all(board[j][i]==player for j in xrange(3)):
                    return True
            # 两条对角线
            return(player==board[1][1]==board[0][0]==board[2][2] or player==board[1][1]==board[0][2]==board[2][0])
        # x的数量一定大于等于o，且相差最大为1
        if onum not in {xnum-1,xnum}: return False
        # 赢家是x，必须保证最后一个棋子是x下的
        if win(board,FIRST) and xnum-1 != onum: return False
        # 赢家是o，必须保证最后一个棋子是o下的
        if win(board,SECOND) and xnum != onum: return False
        return True